The present invention relates to an airbag having a recess portion formed in a head counter portion of an occupant counter surface of the airbag from the occupant side, which confronts the occupant head upon inflation of the airbag. Specifically, the present invention relates to an airbag provided with a regulation member for regulating inflation of the head counter portion toward the occupant. Upon inflation of the airbag, the regulation member regulates inflation of the head counter portion toward the occupant to form the recess portion. The present invention further relates to an airbag device provided with the aforementioned airbag.
The present invention especially relates to an airbag and an airbag device adapted to the passenger seat of the vehicle.
In the specification, an AF05 dummy stands for a legally regulated crash test dummy in the U.S. for a small-sized adult female in 5 percentile. An AM50 dummy stands for a crash test dummy for a large-sized adult male in 50 percentile, which is larger than the female dummy.
In the specification, the small-sized occupant stands for the one with a physical size corresponding to the AF05 dummy. The large-sized occupant stands for the one with a physical size corresponding to the AM50 dummy.
FIG. 25 illustrates a structure of a generally employed passenger airbag.
A passenger airbag device 100 includes an airbag 101, a case 102 and an inflator 103. The airbag 101 is folded to be stored in the case 102, and is inflated by the inflator 103. The case 102 is a container with an opened upper surface which is covered with an instrument panel 104. A windshield 105 is disposed above the instrument panel 104.
Upon supplying gas from the inflator 103, the airbag 101 inflates from the upper surface of the instrument panel 104 to fill the space between the instrument panel 104 and the windshield 105, and the space to the front of the passenger seat. A surface of the inflated airbag 101 to the rear of the vehicle becomes an occupant counter surface 101F opposite an occupant seated on the passenger seat.
In most of the cases, the small-sized occupant will be seated by sliding the seat forward from the backward limit, and the large-sized occupant will be seated without sliding the seat forward.
Generally, the airbag 101 has a sufficient capacity to allow the occupant counter surface 101F to come close to the occupant head upon completion of the inflation even if the occupant is seated without sliding the seat forward.
In the case where the occupant is seated while sliding the seat forward, the occupant counter surface 101F during inflation toward the occupant side may be brought into contact with the occupant head as illustrated in FIG. 25. In such a case, there may be a risk of strong contact between the occupant head and the occupant counter surface 101F.
Japanese Unexamined Patent Application Publication No. 2001-233157 discloses the airbag structured to form a recess portion at a position of the occupant counter surface of the airbag, which is expected to confront the occupant head upon inflation of the airbag. The aforementioned airbag is structured such that the deepest portion of the recess portion is positioned below the occupant chin upon inflation of the airbag, and the tilted surface above the deepest portion of the recess portion confronts the occupant head (face surface).
Upon inflation of the airbag, the tilted surface above the deepest portion of the recess portion is overhung to be positioned rearward of the vehicle as it becomes close to the upper portion of the airbag. In any of the cases where the small-sized occupant is seated by sliding the seat forward, and the large-sized occupant is seated without sliding the seat forward, the tilted surface above the deepest portion of the recess portion may be kept apart from the occupant head by approximately the same distance in both cases during inflation of the airbag.
This makes it possible to prevent strong contact between the head of the small-sized occupant who is seated by sliding the seat forward and the occupant counter surface of the inflating airbag.
In the related art as described above, a lifting cord is provided in the airbag for linking the occupant counter surface of the airbag to the side opposite the occupant. The lifting cord partially pulls the occupant counter surface in the airbag to form the recess portion in the occupant counter surface.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2001-233157
In Japanese Unexamined Patent Application Publication No. 2001-233157, the distance between the occupant counter surface of the inflating airbag and the occupant head is increased when the small-sized occupant is seated without sliding the seat forward.
Generally, the windshield is tilted rearward of the vehicle body as it is closer to the upper end side as shown in FIG. 25. The inflating airbag has the shape having the thickness in the longitudinal direction of the vehicle body smaller as it is closer to the upper portion along the tilted surface of the windshield. The use of the lifting cord to regulate the inflation of the occupant counter surface toward the occupant may cause the risk of insufficient thickness of the inflated airbag in the longitudinal direction of the vehicle body at the upper end side.
Accordingly, an object of the present invention is to provide an airbag capable of effectively restricting the head of the occupant who is seated by sliding the seat forward and the occupant who is seated without sliding the seat forward, and an airbag device provided with the airbag.
Further objects and advantages of the invention will be apparent from the following description of the invention.